A theoretical insight into the microstructure and electronic properties of Ho3+-doped potassium gadolinium tungstate
A theoretical insight into the microstructure and electronic properties of Ho3+-doped potassium gadolinium tungstate
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Ho3掺杂钨酸钾钆的微观结构和电子性能的理论洞察
DOI：
10.1016/j.matchemphys.2020.123824
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发表时间：
2021
影响因子：
4.6
通讯作者：
Ju Meng
中科院分区：
文献类型：
--
作者：
Pan Lu;Xiao Yang;Kuang Xiao-yu;Ju Meng
采用CALYPSO结构搜索方法结合第一性原理计算，系统研究了三价钬离子（Ho 3+）掺杂钨酸钆钾（KGd（WO 4）2）晶体的结构演化.无偏全局最小结构搜索法成功地再现了KGd（WO 4）2的C2/c相标准单斜结构。首次确定了Ho 3+掺杂KGd（WO 4）2体系的最低能级结构，该体系具有与KGd（WO 4）2体系明显不同的单斜构型，空间群为P2。发现杂质Ho ~（3+）离子可以取代Gd ~（3+）离子的格位，形成具有C2格位对称性的[HoO ~（8+）]~（13-）局域单元。我们的电子计算表明，Ho ~（3+）掺杂的KGd（WO_4）_2的能带隙为3.03eV。Ho ~（3+）离子的杂质保留了Ho：KGW系统的绝缘特性。这些结果为理解其他稀土掺杂材料的结构演化和电子性质提供了重要信息。
We have systematically studied the structural evolutions of trivalent holmium ion (Ho3+) doped potassium gadolinium tungstate (KGd(WO4)2) crystals by means of the CALYPSO structure search method coupled with first-principles calculations. The unbiased global minimum structure search is successful in reproducing the standardized monoclinic structure withC2/cphase for KGd(WO4)2. For the first time, the lowest energy structure of Ho3+-doped KGd(WO4)2system is identified, which possesses a significantly different monoclinic configuration withP2 space group. It is found that the impurity Ho3+ions can substitute the sites of Gd3+ions, forming the [HoO8]13−local units withC2site symmetry. Our electronic calculations show that the energy band gap of Ho3+-doped KGd(WO4)2is equal to 3.03 eV. The impurity of Ho3+ion remains the insulating character of Ho:KGW system. These results could provide important information for understanding the structural evolution and electronic properties of other rare-earth-doped materials.